# Integrate product of heaviside function and function of x

#### coverband

How would you integrate product of heaviside function and function of x

i.e. int[f(x)H(x)dx]

Thanks

#### mathman

Are you looking for definite integral or indefinite?

For indefinite, the integral=0 for x < 0 and = the integral of f(x) for x > 0.

For definite integral, integral of f(x) with lower bound ≥ 0.

#### coverband

Thanks

The integral is $$\int_{0}^{2\pi} a^2(sint)^3H(-asint)dt$$

Help !?